Open Access. Powered by Scholars. Published by Universities.®

Medicine and Health Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Saccharomyces cerevisiae

Medical Sciences

2009

Articles 1 - 3 of 3

Full-Text Articles in Medicine and Health Sciences

Minimal Membrane Docking Requirements Revealed By Reconstitution Of Rab Gtpase-Dependent Membrane Fusion From Purified Components, Christopher Stroupe, Christopher M. Hickey, Joji Mima, Amy S. Burfeind, William Wickner Oct 2009

Minimal Membrane Docking Requirements Revealed By Reconstitution Of Rab Gtpase-Dependent Membrane Fusion From Purified Components, Christopher Stroupe, Christopher M. Hickey, Joji Mima, Amy S. Burfeind, William Wickner

Dartmouth Scholarship

Rab GTPases and their effectors mediate docking, the initial contact of intracellular membranes preceding bilayer fusion. However, it has been unclear whether Rab proteins and effectors are sufficient for intermembrane interactions. We have recently reported reconstituted membrane fusion that requires yeast vacuolar SNAREs, lipids, and the homotypic fusion and vacuole protein sorting (HOPS)/class C Vps complex, an effector and guanine nucleotide exchange factor for the yeast vacuolar Rab GTPase Ypt7p. We now report reconstitution of lysis-free membrane fusion that requires purified GTP-bound Ypt7p, HOPS complex, vacuolar SNAREs, ATP hydrolysis, and the SNARE disassembly catalysts Sec17p and Sec18p. We use this …


Phosphoinositides And Snare Chaperones Synergistically Assemble And Remodel Snare Complexes For Membrane Fusion, Joji Mima, William Wickner Sep 2009

Phosphoinositides And Snare Chaperones Synergistically Assemble And Remodel Snare Complexes For Membrane Fusion, Joji Mima, William Wickner

Dartmouth Scholarship

Yeast vacuole fusion requires 4 SNAREs, 2 SNARE chaperone systems (Sec17p/Sec18p/ATP and the HOPS complex), and 2 phosphoinositides, phosphatidylinositol 3-phosphate [PI(3)P] and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. By reconstituting proteoliposomal fusion with purified components, we now show that phosphoinositides have 4 distinct roles: PI(3)P is recognized by the PX domain of the SNARE Vam7p; PI(3)P enhances the capacity of membrane-bound SNAREs to drive fusion in the absence of SNARE chaperones; either PI(3)P or PI(4,5)P2 can activate SNARE chaperones for the recruitment of Vam7p into fusion-competent SNARE complexes; and either PI(3)P or PI(4,5)P2 strikingly promotes synergistic SNARE complex remodeling …


Section Abstracts: Medical Sciences Jul 2009

Section Abstracts: Medical Sciences

Virginia Journal of Science

Abstracts of the Medical Science Section for the 87th Annual Meeting of the Virginia Academy of Science, May 27-29, 2009, Virginia Commonwealth University, Richmond, Virginia.